Method and apparatus for gravel packing wells



H. S. ARENDT ET AL sept. 15,I 1953 METHOD AND APPARATUS FOR GRAVEL PACKING WELLS Filed June 16. 1950 5 Sheets-Sheet l INVENTORS. F G. 2. Harry S. Arendt,

BY Guss F. Ab end'roh,

FIG.

SePf- 15 1953 H. s. ARENDT ET AL METHOD AND APPARATUS FOR GRAVEL PACKING WELLS s sheets-s heel 2 Filed June 16, 1950 'INVENTORS 'f Hdrry S. Arendt,

BY 'Guss AGENY Sept- 15, 1953` H. s. ARENDT ET AL METHOD AND APPARATUS FOR GRAVEL PACKING WELLS Filed June 16, 1950 3 Sheets-Sheet 3 nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nnnn n. l rnnnnnnnnn.

a. no.

- INVENTORS. Harry S. AArendf,

BY Guss F. Abendrofh,

Patented Slept. 115, IQS

UNITED sTATEs PATENT OFFICE METHOD AND APPARATUS FOR GRAVEL PACKING WELLS (ci. 16e-1) 6 Claims. l

The present invention is directed to a method and apparatus for depositing gravel or other similar granular material in either a cased or open borehole. In the present invention a well, in which a cased borehole having perforations arranged adjacent a producing formation of an incompetent material, such as sand, which is susceptible to being washed out, is packed with a bed of gravel or other granular discrete particles. The well is packed by running a producing string defining a screen section including a wash pipe downwardly into the cased borehole to provide an annulus between the producing string and the casing. In such wells, the normal circulation is upwardly through said string to recover the luid produced from the producing formation. In our invention the normal circulation is reversed downwardly through the annulus and outwardly into the producing formation and then upwardly through a bottom opening in the wash pipe under such conditions that the producingiormation and sand or other incompetent material is washed out to form a cavity outside the casing. The flow of washing fluid is directed outwardly into the producing formation by arranging a packer at a point inside the casing adjacent the producing formation such that the reversed flow must pass out into the producing formation and thence back into the annulus to find its way up the tubing string. After the cavity has been washed out the annulus is isolated from upward circulation of fluid by shutting in the casing annulus at the surface. Granular material, such as gravel, in a carrier vehicle, such as water or oil, if desired, is then flowed downwardly into the cased borehole through the wash pipe to deposit in the casing adjacent the producing formation a bed of granular material. The ow of granular material is continued until the cavity has been filled by the granular material squeezing through the perforations in the casing. After the cavity has been filled, the wash pipe and the screen and liner assembly is raised in the cased borehole to a point substantially above the filled cavity while the flow of granular material is continued to extend the height of said bed in the casing. After the bed of granular material has been extended the flow of suspended granular material is discontinued and replaced by an aqueous or oily medium which causes the producing string with the wash pipe assembly to be washed downwardly into the bed to a point adjacent the producing formation. The wash pipe is then retrieved by a Wire line attached thereto and the well is put on production with normal flow from the producing sand to the cavity filled with granular particles, thence into the casing through the bed of granular particles therein and upwardly through the perforations in the strainer of the producing string and thence to the earths surface.

The apparatus of the present invention includes, in combination, a screen and liner adapted to be connected to a producing string. Slidably mounted on the screen and liner is a packer structure, to produce a shut-olf between the casing and the screen and liner and to isolate an annulus between the screen and liner and the well bore. Arranged inside the screen and liner is a retrievable wash pipe which is provided at its upper end and its lower end with separate means for packing off the top and bottom thereof to prevent circulation between the wash pipe and screen and liner at those points. Adjacent a bottom outlet of the screen and liner is a elosure means, such as a dapper-type back pressure valve, which is retracted into an open position by running therein the wash pipe and which assumes a closed position when the wash pipe is retrieved therefrom. The lower end of the screen and liner is offset inwardly to define a recessed portion which denes radial ports. Embracing this recessed portion is a slidable annular sleeve which is adapted to close the radial ports on said recessed portion of said screen and liner when said sleeve is in a retracted position. The screen and liner is provided with perforations or ports which are adapted to be arranged adjacent the producing formation and is further provided with ports medially therein and in the upper end thereof to allow circulation to be continued while the well is being packed in a manner which will be described further.

The invention will be described in more detail by reference to the drawing in which Fig. 1 is a sectional view, showing the assembly being run into a cased borehole;

Fig. 2 is a sectional View of the assembly in position during the washing out operation;

Fig. 3 shows the position of the apparatus of the present invention while gravel or other discrete particulate material is being pumped there- 1n;

Fig. 4 is a further sectional view of the apparatus of the present invention showing the squeezing operation wherein gravel is being squeezed through the perforations of the casing into the cavity;

Fig. 5 is a similar sectional view showing the position of the assembly when the strainer and liner and the wash pipe therein is in raised position to extend the height of the bed;

Fig. 6 is an illustration of the wash down op-s eration;

Fig. 7 is a further showing of the apparatus of the present invention with the wash pipe removed from the well and the well on production; and

Fig. 8 is a view illustrating means to close ori the annulus between the casing and the producing string at the top of the well.

ing in Fig. 2 an internal ush joint screen and; liner I4 is provided with packer. I5. to provide. a.

shut-oif between the casing and screen and liner.

A wire line retrievable wash pipe It, is.. arranged.

within the screen and liner I4 and blanksA off the screen and ports Il of the,producing section and the ports I8 adjacent theA outlet I9. rlhe wash pipe I8 is packed olf at the top by aground'l seat 2K! and at the bottom adjacent the outlet I. by a double O-ring seal 2I. Other known. packing or sealing means may be used. For. example, it. may. be desired to use ground, seats at both top and bottom or sealing rings, cups, packing, and the like. materials available commercially. The wash pipe extends below a dapper-type back. pressure valve 22V which is arrangedbelow the producing section or ports, Il of the screen and liner I4. The wash pipe IGholds the dapper-type back pressure valve 22 in anopen position while the wash pipe li isin the screen and liner I4 but allows it to assume a closed position when the wash pipe I5 isvretrieved.

In Fig. 1 the assembly is being run into the hole andhas not been landedwith the producing sectionv I'I adjacent the producing formation It.

Referring again t Figs. l to "I, the operation of the present invention will be described in more detailin which fluidi movement is described while the assembly is being run into the hole. In this operation the fluid in the hole is free to pass through the open wash pipecontinually fillingthe tubing, the direction ofow being shown in Fig. l as upwardly through theopening I e into the wash pipe to the earths surface andthrough the ports I8 into the annulus A between the wash pipe and the screen and liner If?r and'then outwardly into the annulus A between the casing I I- and the screen and liner I4 by the` producing sectionV I-'I- andn ports 23 and upwardly to earths surface through the'annulus A' between the screen andlliner i4 and-the cas-ing EI.

In Fig; 2 when the screen and liner I4 reaches the bottom, weightis-placed-on the sleeve '1E-4A foron ing it upwardly to-shut oifv circulation through the ports I8. Sleeve 2.4 is theny in the position shown inFig. 2.and maybe heldeither byv spring actuateddogs, by rubber sealrings or by metal tojmetal jfriction; In the drawing, .metal to .metal friction. is. employed but. other, meansA as. illusq trated above may be used. It will be clear that invFig. 2 the packer. I5 is adjusted so its position is adjacent the producing formation I3. Circuf lation is thenreversed with the flow indicated thearrows downwardly through the annulus A' between the casing II and the screen and liner I4. By virtue of the position of the packer I which is slidably mounted on the screen and liner` I4, the flow is causedv to go into the producing formation I3 and thence around the packer into the annulus A' and upwardly through the wash pipe IG and thence to the earths surface. The packer I5 which is slidably mounted on the screen and liner III may be a packer, such as described in the Composite Catalog of Oil Field and Pipeline Equipment, 18th edition, 1951, vol'. l, page 898. On page 898 of the Composite Catalog supra, the Brown Oil Tools, Inc. Duo- Pak all purpose packer is described. This packer may be moved with respectl to the screen and liner I4 in the following manner: Referring to 4. Fig. l, it will be seen that the packer I5' on the screen and liner I4 is being lowered in the casing;` II until it reaches a point, as is shown in Fig.A 2',.for washingA out the cavity 25 as will be described" in more detail hereinafter. The packer- I5. isnot set but. it. affords a sufficient seal to' allow the. cavity tot be washed out as indicated' by' thev arrows. showing the flow. Thus, after the. cavity. 25; iswashed out, as shown in Fig. 3,A the assembly including the packer I5 is then` raised in the casing I I by lifting up on the screen` andli'ner I4 until the packer I5 has reached the position shown in Fig...3 at which point the' latching means holding thev packer I5 to the screen andi liner I 45 is=released by rotating the pipe string or by other means and the packer I5 set against the interior wall of the casing II'.y After the packer I5 is set against the wall of the casing II, such as by setting down weighton the pipe string, the screen and liner I4 may be moved freely through the packer I5; thus the screen and. liner I4 serves as a packer mandrel and is freelyv movablefthrough the packer so that..

the screen and liner I4l may be lowered tothe point shown in Fig. 3 to deposit the finely divided.. materials, such as gravel, in the casing II. rThereafter, the packer I5 remains in position until the cavity. 25 hasv been filled. It is` only necessary to move thefscreen andliner I4 through thepacker, such as shown in Fig. 5, wherein the screen and liner I4 is raised upwardly in the casing II to allow the. gravel to be depositedin. the casing.

As shown in Figs; 6Y and '1, since the packer I5 has been set against the casing II thev screen and liner I4 may be moved freely through the packer to allow the screen and liner It to washed downwardly to set the apparatus of the present invention on bottom.

It may be desirable. after. setting the device of the present invention to, latch the packer I5. against the screen and liner to obtain. a permanent installation. However, employment of packers such as illustrated in the Composite Catalog supra do not require latching of the packer against the screen and liner Ilisince an effec.- tive seal may be obtained Without. av permanent latch.

A more detailed descriptionlof the gravel pack ing operation follows: By Virtue of theiiow conditions which are suitably adjusted, the sand in producing formation I3, being of an incompetent nature, is washed out andA bach into the annulus A' and up into the wash pipe causing the formation of a cavity 25. After the cavity has been suitably washed out the assembly includingy the screen and liner I4, the wash pipe I6, andthe packer I5` is raised byv raising upon the producing string. The packer, which is siidably mounted on screen and liner, I4 and which may` be latched thereto by means not. shown, is adjusted toa position as indicated in Fig. 3. A suspension or mixture: 25. of gravel orjother granular particles is then flowed downwardly through the wash pipe. I6 into thebottom of the, cased borehole II. to cause the formatontherein. of a bed of granular particles. 2l. The suspension afterxdepositing the granular. particles therefrom allows the liquid vehicle or carrier. fluid toproceed upwardly through they annulus Af between. the screen and liner I4..and` casing I I and thence through the ports or producing. section I'I into the annulusA betweenthe wash pipe I5 andthe screen and liner I4 and upwardly therethrough -to a point above the packer I5 Where the flow then proceeds as indicated by the arrows through the ports 2S back into the annulus A between the screen and liner I4 and the casing I I. After the bed 2l of granular material has been deposited into casing Il to a suitable height as indicated in Fig. 3, blow-out preventers 50, such as shown in Fig. 8, and/or other means are closed, directing the flow through the perforations I2 into the formation I3 with the velocity of flow carrying the gravel through the perforations to fill the cavity 25 as shown in Fig. 4, the liquid vehicle being forced into the earth formation as indicated by the arrows designating the flow thereof. This operation is continued until gravel from the bed 2l completely lls the cavity 25 forming a bed 2s therein. Thereafter the flow is continued while raising the assembly to a point substantially above the cavity 25 in producing formation I3, as shown in Fig. 5. The addition of granular material to the fluid stream is then terminated. The blow-out preventers 50 are opened and flow as indicated in Fig. 6 is begun, which causes the assembly including the screen and liner is and the wash pipe I6 to be washed back downwardly through the bed 2'I, the flow being indicated by the arrows with the fluid passing outwardly into the bed 2'I through the outlet I9 and back into the annulus A between the screen and liner I4 and the wash pipe I6 through ports I'I and upwardly therethrough and outwardly through ports 28 into the annulus A between the casing I I and the screen and liner I4 and thence to the earths surface. Some of the flow will be from the outer annulus A into the inner annulus A by ports 23. After port 28 enters the packer I 5, the lower portion of the outer annulus A is isolated with the assembly including the screen and liner I4 being in the desired position. The wash pipe I6 is then retrieved by a suitable wire line (not shown). The packer had been previously set in the predetermined position before placement of gravel was started and serves as a tubing packer. In Fig. 7 the wash pipe has been retrieved and the dapper-type back pressure valve 22 is shown in a closed position causing the oil or other medium to be produced from producing formation I3 to flow through cavity 25 containing the granular materials 29 and thence through bed 21, through the perforations i'l and upwardly through the producing string to the earths surface, the flow being shown by the arrows.

After the screen has been washed to the bottorn, as indicated in Fig. '7, and the wash pipe IB removed, the Christmas tree may then be placed on the well and the well placed in operation, as shown in Fig. 7.

The method of the present invention increases the safety of operations and reduces rig time. rIhe method and apparatus of the present invention allows a well to be packed with gravel or other granular materials with a half round trip as contrasted to two and one-half to four and one-half round trips with the pipe when employing the methods and apparatus heretofore available to the industry, one round trip including running the pipe in the hole and removing it from the hole. Furthermore, the apparatus and method of the present invention eliminate the necessity of pulling the cavity washing packer or tool assembly and also eliminates the attendant danger of swabbing the well in. The absence of round trips also avoids objections to having salt or fresh water or oil in the hole during a trip and thus eliminates the several changes from drilling mud to salt water or other liquid media and back. The employment of salt water or other liquid throughout the operation also avoids contamination of the gravel pack and sand face with mud filter cake. Experience has indicated that contamination of the gravel pack and sand face results in partial plugging of the sand face and/or gravel pack with consequent reduction in well potential. The method of the present invention also avoids the danger of gravel sticking the wash tool which currently exists when the gravel is placed with the wash tool in the hole. The method is also usable in gravel packing shaly sections and gravel packing in open holes using salt or fresh water or oil.

In employing the present invention in an open hole, the circulation is reversed as has been described with respect to Fig. 2 to clean out the hole and to remove any filter cake which may have deposited on the face of the producing formation. Reversal of circulation may also result in washing out a cavity if none existed before or enlarging an existing cavity. Thereafter a mixture or suspension of gravel or other granular, particulate material is flowed downwardly into the open hole to ll the cavity or borehole with the granular material, the liquid vehicle or carrier fluid being forced into the earth formations as has been described. The remaining steps of raising the assembly and washing back down are as has been described previously.

In some formations where the structure is of such an incompetent nature that it tends to Slough even when a pressure diierential is applied against the formation, it is possible to Wash out the sand while depositing granular material in the formation. In effect because of the different settling rates of the incompetent material and the granular particles, it is possible to conduct the washing out and depositing operations practically simultaneously, the velocity of flow of the carrier medium to the surface being adjusted to deposit the granular material and carry out the material Washed from the formation.

The nature and objects of the present invention having been fully described and illustrated, what we desire to claim as new and useful and tosecure by Letters Patent is:

l. A method for packing a borehole in a producing formation susceptible to being washed out in which a pipe string defining a screen section has been run including a wash pipe arranged therein wherein the normal circulation from the producing formation is upwardly through said string, which comprises flowing a washing fluid downwardly through an annulus between the pipe string and the borehole and upwardly through said pipe string, directing said flow of washing fluid into said producing formation and outwardly therefrom to wash a cavity in said formation and to wash and clean a portion of said borehole adjacent said producing formation, flowing a mixture of granular material in a liquid carrier vehicle downwardly in said borehole through said wash pipe to deposit a bed of granular material in said borehole adjacent said producing formation, isolating the borehole from upward circulation, continuing the flow of granular material until said washed portion of said borehole adjacent said producing formation has been filled with granular material, raising said pipe string and wash pipe in said borehole to a point substantially above said filled portion of said borehole while continuing the flow of granular material to extend the height 'of said bed,

discontinuing the flow of granular material, flowing a liquid medium downwardly in said borehole through said wash pipe to wash said pipe string and wash pipe downwardly into said bed adjacent said producing formation, and removing said wash pipe from said borehole.

2. A method for packing a well in a cased bore-Y hole having perforations arranged adjacent a producing formation susceptible to being washed out and in which a producing string defining a screen section has Vbeen run' including a wash pipe arranged therein to provide an annulus between said producing string and said casing wherein the normal circulation from the produc.- ing formation is upwardly through said string, which comprises nowing a washing iiuid downwardly through said annulus and outwardly into said producing formation and thence upwardly through a bottom opening in said wash pipe to wash out said producing formation to form a cavity outside said casing in said producing formation, flowing a mixture of granular material in a liquid carrier vehicle downwardly into said cased 'borehole to deposit therein -a bed of granular material adjacent said producing formation, isolating the annulus from upward circulation, continuing the now of granular material until said cavity has been iilled with granular material squeezing through said perlorations from said bed, raising said producing string and wash pipe in said cased borehole to a point substantially above said filled cavity while continuing the now of granular material to extend the height of said `bed in said cased borehole, discontinuing the ow of granular material, flowing a liquid medium downwardly through said wash pipe to wash said producing string and wash pipe downwardly into said bed to a point adjacent said producing formation, and removing said wash pipe from said well.

3. A method for packing a well in a cased borehole having perforations arranged adjacent a producing formation susceptible to being washed out which comprises running a producing string having a screen section including a wash pipe `arranged therein into said cased borehole to provide an annulus between said producing vstring .and said casing wherein the normal circulation from the producing formation is upwardly through said string, flowing a washing uid in .said well downwardly through said annulus and outwardly into said producing Iformation and thence upwardly through a -bottom opening in said wash pipe to wash out said producing formation to form a cavity outside said casing in said producing formation, flowing a mixture of granular material in a liquid carrier vehicle downwardly into said cased borehole to deposit therein a bed of granular material adjacent said producing formation, isolating the annulus from upward circulation, continuing the flow of granular material until said cavity has been lled with granular' material squeezing through said perforations from said bed, raising said producing string and wash pipe in said cased borehole to a point substantially above said lled cavity while continuing the flow of granular material to extend the height of said bed in said cased borehole, discontinuing the flow of granular material, flowing a liquid medium downwardly through said wash pipe to wash said producing string and wash pipe downwardly into said bed to a point adjacent said producing formation, removing said wash pipe from said well and producing said well.

4. Apparatus for packing a well with granular material which comprises, in combination, a screen and liner provided with spaced apart ports arranged at an intermediate point and adjacent an upper end thereof and said screen and liner defining a lower outlet with a lower end thereof, said screen and liner being adapted to be connected to -a producing string, a packer slidably mounted on said screen and liner adapted to direct now into and out of said screen and liner on positioning said packer between the spaced apart ports, a retrievable wash pipe adapted to `be retrieved by a wire line attached thereto arranged with said screen and liner, separate means for packing off the top and the bottom of said wash pipe to prevent circulation between said wash pipe and said screen and liner, closure means arranged in said screen and liner adjacent said lower outlet which is adapted to beheld in an open position when said wash pipe is in said screen and liner and adapted to close said lower outlet of said screen and liner when said wash pipe is retrieved to allow now from said producing formation upwardly through said screen and liner and through said producing string on positioning said packer above the ports adjacent the upper end of said screen and liner.

5. Apparatus in accordance with claim 4 in which the screen and liner defines radial ports immediately above the lower outlet, and in which a slidable annular sleeve is arranged on said screen and liner adapted to close said radial ports when said sleeve is in a retracted position.

6. Apparatus for packing a well with granular material which comprises, in combination, a

screen land liner provided with spaced apart ports arranged at an intermediate point and adjacent an upper end thereof defining with a lower end thereof a recessed shoulder having radial ports communicating the exterior with the interior thereof and defining a lower outlet with said lower end, said screen and liner being adapted to be connected to a producing string, a packer slidably mounted on said screen and liner adapted to direct iiow into and out of said screen and linerV on positioning said packer between the spaced apart ports, a retrievable wash pipe adapted to be retrieved -by a wire line attached thereto mounted within said screen and liner, separate means for packing olf the top and bottom of said wash pipe to prevent circulation between said wash pipe and said screen and liner, closure means arranged in said screen and liner adjacent said lower outlet which is adapted to be held in an open position when said wash pipe is in said screen and liner and adapted to close said lower outlet when said wash pipe is retrieved to allow flow from said producing formation'. upwardly through said screen and liner and through said pipe string on positioning said packer `above the ports adjacent the upper end of said screen and liner, and a slidablc annular sleeve embraceably mounted on said recessed shoulder adapted to close said radial ports when said sleeve is in a, retracted position.

' HARRY S. ARENDT.

GUSS F. ABENDRO'I'H.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 2,207,334 Reynolds etv al July 9, 1940 2,229,493 Croft et al Jan. 21, 1941 2,310,397 Cyoberly."` g Feb. 9, 1943 2,349,062 Vren May 16, 1944 

